sort applied after CCE-TO-REG mapping post interleaving

Hi,

I was going through matlab example DownlinkControlProceduresExample.m in 2020a wherein in the function nrPDCCHSpace.m function you are generating PDCCH indices, I could see that post interleaving, sorting of the indices are applied which wasnt there in 2019b version. Can you explain with a corresponding reference for this change?

Answer 1

[Sriram Tadavarty]

Hi Yatin,

The "sort" is used to effect the frequency-first filling *per OFDM symbol* for the resource blocks within a control channel element (CCE).

TS 38.211 Section 7.3.2.5, stats this as "...mapped to resource elements … in increasing order of first k, then l."

where k is the index for the subcarrier and l the OFDM symbol.

Hope this helps.

Regards,

Sriram